Evaluate patient lifestyle, visual needs when fitting specialty contact lenses

Issue: September 1999

When prescribing specialty contact lenses such as bifocals and toric lenses, the practitioner should keep certain guidelines in mind for fitting the patients who will be wearing them. Presbyopic patients who choose to try bifocal lenses may require time to grow accustomed to their new zones of corrected vision, and those with astigmatism should be prescribed whichever type of toric lenses will work best for their lifestyle, whether they be soft or rigid gas-permeable lenses (RGPs).

Fitting a patient with special visual needs is a process that begins with a debriefing by the optometrist on what meeting those needs actually entails, said Thomas G. Quinn, OD, MS, in group practice in Athens, Ohio. “The first thing a doctor needs to do is make sure patients understand their visual conditions,” he noted. “If they understand the situation, they will understand that they need a special design that will cost more.”

Secondly, he said, doctors should demonstrate in real terms what their vision would be like if it were not corrected appropriately. Patients with astigmatism, he said, often are familiar with the word but do not know how the condition directly affects their lifestyle. “When patients are behind the phoropter, I will leave their nearsighted correction in, but I’ll take the astigmatism correction out so they can see what happens,” Dr. Quinn said. “This way, they understand why we need to correct the astigmatism and how its correction affects them in a very personal way.”

Prescribing bifocal lenses

While the popular soft bifocal lenses, such as Acuvue (Vistakon, Jacksonville, Fla.), tend to be in the forefront of many people’s minds, practitioners should not overlook the benefit of RGPs for certain patients, said Joseph Stamm, OD, in private practice in Rochester, N.Y. “If I can, I prefer to use gas-permeable bifocals, because I find that vision is far superior than with the soft bifocals. However, I have been using the Acuvue bifocal for a little over a year, and I’m very impressed with it,” he said. “But, there does tend to be a little bit of compromise in the distance vision that you don’t always get with a gas-permeable bifocal.”

Dr. Stamm said that he will recommend the Lifestyle GP (The LifeStyle Co., Morganville, N.J.) or the Essential RGP (Blanchard Contact Lens Inc., Manchester, N.H.) for his presbyopic patients first. However, not everyone is well suited for this type of lens, he cautioned. “Not everyone wants to work with a gas-permeable contact,” he said. “Not everyone’s prescription is conducive to working with that type of lens. When it’s appropriate, that’s my first recommendation.”

Keep an open mind about RGP bifocals

Patients need to experience an RGP bifocal lens before deciding prematurely that the fit will not be a comfortable one, said Rhonda S. Robinson, OD, in private group practice in Indianapolis. “That’s a misconception,” she said. “I think most people are surprised when we put their new bifocal gas permeable lenses on, especially when they see so sharply. I would suggest to practitioners who have not gone that route to have more of an open mind about fitting RGP lenses. The laboratories can help them out either with a trial set or by helping them decide what power to use.”

The Acuvue bifocal is the first choice of Dr. Quinn for presbyopic patients with less than 0.75 D of astigmatism due to its wide range of success, he said. “The Acuvue is my first choice basically because it works well on many people, and I like the 2-week replacement option,” he noted. “My second choice is the Additions, by Sunsoft [Albuquerque, N.M.]; that’s a nice complement to the Acuvue, which is a center-distance design, where the Additions is a center-near lens. If one doesn’t work on a given individual, the other one might.”

Dr. Quinn said the Acuvue’s 2-week replacement schedule is favorable for presbyopic patients who may experience significant protein build-up. “Particularly with a bifocal, I think the 2-week replacement has obvious advantages because patients are further along in their life cycle and they tend to have more problems with tear quality and are more prone to coat lenses,” he said.

For astigmatic presbyopic patients who spend a good portion of their time viewing a computer screen, Dr. Quinn pursues correction with an aspheric RGP design. If a high demand for crisp near vision is required, a translating RGP design may serve the patient better.

Finding the right toric lens

RGP lenses may be superior to soft lenses for patients suffering from astigmatism as well, said Lee Rigel, OD, in private group practice in East Lansing, Mich., mostly in terms of visual clarity. “Rigid lenses correct corneal astigmatism completely and very effectively, typically offering the patient better, crisper visual acuity than soft toric lenses,” he said. “Unfortunately, I see a tendency for practitioners to reach for soft toric lenses more now because of their availability than to go to RGPs, even though RGPs may be better for the patient from a visual acuity standpoint.”

Dr. Robinson added that while patients may enjoy slightly sharper vision with an RGP toric lens, patients new to contact lenses may fare better by starting out with a soft lens to ease the transition. “Some patients who have never worn lenses at all are a little bit wary, so you might want to start off with a soft lens just because adaptation might be a little easier,” she said. “Then once they’re used to having something in their eyes and if you’re not able to get success with the soft lens, it’s easier to switch them over to a rigid lens.”

A patient with a higher prescription, a higher cylinder and an oblique cylinder may have more success with a gas permeable lens, said Dr. Stamm. And he said that while RGPs may boast better resolution, generally speaking, than soft lenses, they are otherwise comparable. “There isn’t the visual compromise with a soft toric like there is with a soft bifocal,” he said. “They’re very different animals. Whether I use a gas perm with a patient or a soft lens depends on what’s most appropriate for the patient and what the patient’s needs and requirements are for the lens.”

Soft torics for active patients

The practitioners agreed that astigmatic patients who are very active and play high-contact sports are better off wearing soft lenses to prevent lens displacement. “I will tend to go toward a soft contact lens when a patient is very active,” said Dr. Stamm. “During these times, the gas permeable lens has a greater chance of popping out, and there’s a greater risk of getting debris underneath the lens.”

Frequent-replacement soft lenses such as SofLens 66 (Bausch & Lomb, Rochester, N.Y.), FreshLook Toric (Wesley Jessen, Des Plaines, Ill.), Frequency 55 (CooperVision, Irvine, Calif.) and Focus Toric (CIBA Vision, Duluth, Ga.) tend to be the most prevalent choices among practitioners in the toric arena. Dr. Robinson said that she will recommend the SofLens 66 for patients who prefer the notion of a frequent-replacement lens. “It’s really nice for patients who need a toric in one eye and a sphere in the other, but they’ve been wearing two spherical lenses and putting up with one eye not being as crisp because they want to be in a 2-week modality,” she said. “Now we can sharpen that eye, and both eyes can be on the same schedule, which is nice.”

Dr. Quinn said that choosing one soft toric lens over the other depends on the ultimate goal for the patient. “The SofLens 66 is often my first choice, because it’s generally a very stable and comfortable lens,” he said. “If it’s not stable, then we’ll go to the FreshLook Toric, because commonly that will be even better stability-wise but it may not be quite as comfortable.”

Using topography to fit specialty lenses

The practitioners all touted the benefits of using corneal topography when fitting patients for specialty lenses. “I find that it’s more helpful in fitting rigid lenses, especially if we’re re-fitting patients and we want to make sure the cornea is stable,” said Dr. Robinson. “It is really nice to be able to monitor slight changes in the cornea from one week to the next.”

While a topographer aids in assessing the change in the shape of the cornea from the center to the edge, Dr. Quinn said that a trial-and-error method would be more appropriate for prescribing bifocal lenses. “When it comes to bifocal lenses, I feel strongly that you definitely need to put the lens on the eye to assess it because of pupil sizes and individual sensitivities,” he said. “The only way to really know how a bifocal contact will work is by putting it on the eye and assessing the vision.”

Dr. Rigel added: “We do a lot of corneal topography, and we certainly look at that as part of the process, but that’s not the determining factor for which lenses we’re going to use,” Dr. Rigel said. “We look at that as a baseline, but we do all of our fitting from fluorescein patterns and trial lenses. Occasionally we may even fit empirically.”

When choosing the correct lens for a patient, Dr. Stamm noted that all too often practitioners tend to underestimate the effect of a small amount of astigmatism, which can result in vision that is not what it should be. “A lot of doctors don’t think of reaching for a toric lens if a patient has 0.75 D of cylinder,” he said. “But it can make all the difference in the world. Never underestimate the impact a small amount of astigmatism can have on a patient’s vision.”

Coaching bifocal and toric lens patients

Preparing patients, especially bifocal patients, for what to expect with their new lenses is important from the beginning, said Dr. Quinn. “Set their expectations at a reasonable level,” he said. “Especially with bifocal patients, if they get the contacts and they think it will allow them to see like they did when they were 20, they’re going to be disappointed. I tell every bifocal patient that my goal is to meet most of his or her visual needs most of the time. I always say there are compromises with every form of correction.”

Dr. Rigel added that taking the patient’s lifestyle and career choice into consideration is crucial before the lens-fitting process begins. More detail-oriented individuals who are required to study numbers and words closely most likely would not benefit from bifocal lenses as much as others. “Some engineer types say that they want to wear contact lenses and see as well as they do in glasses, if not better,” he said. “They don’t want any hassles as far as putting them in and taking them out, seeing the computer screen, reading fine print on a medicine bottle and seeing 20/20 distance all the time. This very likely is unrealistic.”

Toric lenses typically are not as difficult for patients to adjust to as bifocals. However, if they are composed of a rigid material, it may take some time to adapt. It also requires a bit of trial-and-error to find the right lens, said Dr. Stamm. “I tell the patients that there are a lot of variables involved with a toric lens,” he said. “It’s like juggling four or five balls at one time. Very often, the first lens isn’t going to be the final lens. They have to adjust for rotation and for position of the contact on the eye. If you tell patients right up front that this isn’t going to be easy or straightforward, they’re prepared. When they come back and say their vision is a little bit variable, they will have been expecting it. So you don’t lose patients’ confidence, and they don’t get frustrated.”

Dry eye: A special-needs patient?

Wearing contact lenses can often aggravate a dry eye condition. Before attempting to fit a dry eye patient with a contact lens, said Dr. Stamm, evaluate the tear film to see if he or she is really a candidate for contacts. “Part of my initial evaluation is the evaluation of the tear film and tear stability, because, as I tell the patient, if there’s going to be a problem, I want to know about it,” he said. “If we can address it, we want to address it right up front. If the patient has an extremely poor tear film, I may say that he or she is not a good candidate for contacts.”

Practitioners recommend that, for dry eye patients, thicker lenses boasting a low water content are preferable to help prevent dryness. Frequent replacement lenses, as well, may help reduce the incidence of ocular dryness. “Certainly, disposable products can be beneficial, because a cleaner lens is going to wet better than a lens that has debris attached to it,” Dr. Rigel noted.

Sometimes, the key to relieving what feels like dry eye symptoms to the patient is as simple as switching the lens care system from a chemical-based one to a hydrogen peroxide-based system. “Patients can really be having a low-grade sensitivity to the chemical, which they express as a dry eye feeling,” Dr. Quinn suggested. “The reason we don’t start everybody on hydrogen peroxide is because it’s more cumbersome. We figure the easier the regimen is, the more likely patients are to comply, so we always start with a chemical system. But if they have these vague dry eye symptoms, and you look at the tear quality and it looks OK, simply switching their care system can really make a difference.”

The process often becomes a trial-and-error approach, testing different lens brands and water content levels. Additionally, some dry eye patients will benefit from using adjunct products such as lubricating drops and punctum plugs. Dr. Stamm said that by employing an educated trial-and-error method, a practitioner can make the best assessment of the information at hand.

“If you have all the facts about the patient in front of you, you can make a more intelligent decision as to which contact lens should be your first lens of choice,” he said.

For Your Information:

Thomas G. Quinn, OD, MS, is in group practice and may be reached at 416 West Union St., Athens, OH 45701; (740) 594-2271; fax: (740) 594-2270. Dr. Quinn has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Joseph Stamm, OD, is in private practice and is a clinical associate in the department of ophthalmology at the University of Rochester. He may be reached at 1815 South Clinton Ave., Ste. 435, Rochester, NY 14618; (716) 271-2210; fax: (716) 271-7274. Dr. Stamm has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Rhonda S. Robinson, OD, is in a private group practice specializing in contact lenses and is also an academic consultant for Bausch & Lomb. Dr. Robinson has no direct financial interest in the products mentioned in this article. She may be reached at Schuff Robinson Optometry, 6137 Crawfordsville Rd., Indianapolis, IN 46224; (317) 243-0028; fax: (317) 243-0805.

Lee Rigel, OD, is in private group practice with a high emphasis on contact lenses. He may be reached at Vision Care Associates, 310 West Lansing Rd., East Lansing, MI 48823; (517) 337-8182; fax: (517) 332-0038. Dr. Rigel has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.